Investigation of the Failure of a High-Pressure Pump Motor Bearing Oil Cooler

摘要

1) The failure of the oil cooler tube is attributed to localized pitting caused by the synergistic action of lowear-stagnant water velocity, the induction of subsequent stresses, and the formation of HAZ during weld solidification. Low or near-stagnant water velocity was caused by the obstruction in the flow path because of improper welding. The presence of sulfur compounds and the high chloride content in the water contributed to accelerating the failure. The cause of an earlier failure in the cooling coil tube may be the built-in defective joining of the flange with the sea-water outlet tube.